#include <stdio.h>
main()
{ 
FILE*fp;
int i, a[6]={1,2,3,4,5,6},k;
fp = fopen ("data. dat", "w+b");
fwrite(&a[0], sizeof(int), 1,fp);
for (i=1; i<6; i++)
{ 
fseek(fp,0L,0) ;
fread(&k,sizeof(int),1,fp);
fseek(fp,0L,0);
a[i] +=k;
fwrite(&a[i], sizeof(int),1, fp);
}
rewind(fp);
fread(&k,sizeof(int),1,fp);
fclose(fp);
printf("%d\n",k);
}
